My dad refused to tell me what's he apologizing for when apologizing, so his apologies were kinda insincere and a way to show that he can do shit behind my back and then just "apologize" and pretend it's something good.

He was messing in things not his to deal with in the first place. Thinking he's the smart one there. Naturally it generally wasn't so, and then he never answered any questions I'd ask.

Now he's also dead, so I can't even ask him again.

OK. Back to the subject - parents should be honest and consistent, and also always understand that their kids are different people, and no part of them belongs to the parents. And that no, parents don't know better. When the moment comes that a parent's advice is consciously rejected, they should just take it. When they are not let into something, that means it's not their concern, period.